No, this is not a story of days of old – sorry. It’s about two groups of insects which had a wonderful time in our recent big Wet: damselflies and dragonflies. I saw far more this year than ever before, and an online friend from Exmouth, WA, says the same.
Damsels are (appropriately enough) generally smaller and more delicate than dragons but both families are aerial predators, hunting on the wing. The easiest way to tell them apart is that damsels fold their wings over their abdomens when resting, whereas dragons hold them outstretched or forwards and downwards. The two groups, Zygoptera and Anisoptera respectively, make up the order Odonata. There are some 320 species in Australia, mostly in the north.
They are an ancient order – every prehistoric-nature doco seems to mention the enormous dragonflies of the late Paleozoic, 300 million years ago, when greater oxygen content in the air allowed them to reach wingspans of 70 cm.
Adults lay eggs in fresh water, where the larvae (also carnivorous) develop through several moults before crawling up into the air to split open, much as cicadas do, to emerge as adults. Adults can roam far from water but must return to breed and the abundance of dragonflies is a good indicator of a healthy ecosystem. Their mating behaviour is complex and quite strange. Read about it here if you don’t want to wait until I can find time to write about it.
Dragons and damsels have no economic significance to us but are universally loved for their beauty and agility in the air.
More about damsels and dragons
This article first appeared in a slightly different form in Kapok, newsletter of Coastal Dry Tropics Landcare, Inc., in March 2011.